1. The field of the invention comprises catheters for removing occlusive material from blood vessels.
2. Description of the Prior Art. In a conventional catheter for removing occlusive material such as plaque and emboli, a stylet wire covered with a soft flexible tubing is joined with a luer lock connection to a symmetrically inflatable latex balloon. The balloon has a softer distal tip which is inserted past the stenosis of the blood vessel with said balloon deflated. The balloon is then inflated by means of air pressure through said tubing, and the catheter is then retracted, accumulating occlusive materials before the posterior portion of the balloon during the withdrawal process.
"Over a seven-year period, during which time approximately 500 such balloon tipped catheters have been used in surgical procedures, six complications have been recognized. These were the disruption of the posterior tibial artery, perforation of the popliteal artery, breaking off of the catheter tip in the profunda femoris artery, disruption of an intra-hepatic bile duct, and two disruptions of saphenous vein in situ grafts while rendering valves incompetent." (Reprinted from the Archives of Surgery, July 1972, Vol. 105, American Medical Association, pp. 79-82)
The described types of arterial injuries, including arterial rupture, arterial perforation, and intimal wrinkling, often lead to intimal disruption. Risk of such arterial injuries is greatly lessened with this invention by the absence of a distal tip. Intimal wrinkling would be minimal or non-existent upon insertion. Chances of damage to blood vessels of sufficient size to accept this invention would be greatly lessened and extremely remote. The introduction of lubricants for dissolving or entraining the cut occlusive material or debris, a fiber optic light and lens, and healing agents in solution or suspension through said catheter are capabilities not present in existing catheters.
Another catheter equipped with a high speed, air pressure driven rotary blade employs a guidewire which passes through the lumen, or bore, of the catheter and across the stenosis. The rotating cutter is thereby moved forward to dissect the occlusive plaque. No means is provided for removing the reduced occlusive material from the blood vessel. This procedure is described in Cardiovascular News, McMahon Publishing Co., February 1986, pp. 1 and 4.